US20180317916A1 - Knife With Mechanical Fuse - Google Patents

Abstract

A knife member that can have a blade portion configured operation within a surgical stapling device. A first frame portion can extend from the blade portion to a first connection portion. A second frame portion can extend from the first frame portion to a second connection portion. At least one of the first and second frame portions can include a fused portion. The fused portion can be configured to fail when a predetermined amount of force is applied to the fused portion.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• The present application is a U.S. National Stage application of PCT/US2016/059297 filed Oct. 28, 2016, which claims priority to, and the benefit of, U.S. Provisional Patent Application 62/251,838 filed Nov. 6, 2015, the full disclosures which are incorporated herein by reference in their entirety for all purposes.
BACKGROUND OF THE INVENTION
• Surgical clamping and cutting instruments (e.g., linear clamping, stapling, and cutting devices, also known as surgical staplers; and electrosurgical vessel sealing devices) have been employed in many different surgical procedures. For example, a surgical stapler can be used to resect a cancerous or anomalous tissue from a gastro-intestinal tract. Many known surgical clamping and cutting instruments, including known surgical staplers, have opposing jaws that clamp tissue and an articulated knife to cut the clamped tissue.
• In the case of telesurgical controlled instruments, surgical clamping and cutting instruments are often deployed into restrictive body cavities (e.g., through a cannula to inside the pelvis). Accordingly, it is desirable for a surgical clamping and cutting instrument to be both compact and maneuverable for best access to and visibility of the surgical site.
• Surgical clamping and cutting instruments can sometimes fail to fully actuate (e.g., due to a hard obstacle blocking the knife path). In such an event, it is desirable that the knife blade not be in a position that may represent a hazard with respect to removal of the surgical instrument from the surgical site. Known surgical clamping and cutting instruments, however, may fail to avoid the potential knife hazard and at the same time be compact and maneuverable.
• Thus, there is believed to be a need for improved surgical clamping and cutting instruments and related methods. Such surgical clamping and cutting instruments should be compact and maneuverable, and employ a knife that does not represent a hazard with respect to removal of the surgical instrument from the surgical site when the surgical instrument fails to fully actuate.
BRIEF SUMMARY OF THE INVENTION
• Some embodiments of the invention relate to a knife member. The knife member can have a blade portion configured for operation within a surgical stapling device. A first frame portion can extend from the blade portion to a first connection portion. A second frame portion can extend from the first frame portion to a second connection portion. At least one frame portion of the first frame portion and second frame portion can include a fused portion, and be terms a fused frame portion. The fused portion can be configured to fail when a predetermined amount of force is applied to the fused portion.
• Some embodiments of the invention a surgical stapling cartridge. The cartridge can be configured to removably attach to a jaw of an end effector and have a plurality of staples arranged along a slot. A drive member can be configured to travel along the slot. A knife member can be configured to be carried by the drive member and have a blade portion that extends above the slot. The knife member can have a fused portion configured to fail and recede beneath the slot when a predetermined amount of force is applied to the fused portion.
• In some embodiments, the fused portion can be a notched portion.
• In some embodiments, the fused portion can be a relatively thin section relative to part or all of the remainder of the first frame portion or second frame portion.
• In some embodiments, the fused portion can fail by fracturing.
• In some embodiments, the fused portion can fail by bending.
• In some embodiments, the first frame portion or second frame portion can have an opening.
• In some embodiments, the fused portion can be proximate to the opening.
• In some embodiments, the first frame portion or second frame portion can include a first strut and a second strut, with the first strut being separated from the second strut by the opening.
• In some embodiments, the fused portion is a notched portion of the first strut.
• In some embodiments, the second frame portion can be an elongated strut.
• In some embodiments, the elongated strut can be configured to elastically deform into the fused portion.
• In some embodiments, the first frame portion and the second frame portion can have a laminated construction including a first sheet and a second sheet.
• In some embodiments, the blade portion and the fused portion can be located on the second sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of a robotic surgery tool that includes an end effector having opposed clamping jaws, in accordance with some embodiments.
• FIG. 2 is a perspective view of a demountably attachable cartridge of a linear stapling and cutting surgical instrument having six rows of staples, in accordance with some embodiments.
• FIG. 3 is a perspective view of the cartridge ofFIG. 2 and an attached staple retainer, in accordance with some embodiments.
• FIG. 4 is a cross-sectional view showing attachment details between the cartridge ofFIG. 2 and an end effector assembly, in accordance with some embodiments.
• FIG. 5 is an exploded perspective view illustrating components of the cartridge ofFIG. 2.
• FIG. 6 is a cross-sectional view of a demountably attachable cartridge of a linear stapling and cutting surgical instrument, in accordance with some embodiments.
• FIG. 7A illustrates the actuation of the knife member of the cartridge ofFIG. 7.
• FIG. 7B shows a housing receptacle that receives a protrusion of the knife member to restrain the knife member from moving distally during a movement of the drive member distally, in accordance with some embodiments.
• FIG. 7C shows the knife member coupled with the drive member while the drive member drives the knife member distally, in accordance with some embodiments.
• FIG. 7D shows the knife member at the end of the actuation stroke after the distal end of the knife member has been driven along a cam surface of the housing to raise the distal end of the knife to lower the knife blade of the knife into the housing, in accordance with some embodiments.
• FIGS. 8A-8C show side views of knife members having mechanical fuses, in accordance with some embodiments.
• FIG. 8D shows a failure mode of knife member having a mechanical fuse, in accordance with some embodiments.
• FIGS. 9A-9C show side views of knife members having mechanical fuses, in accordance with some embodiments.
• FIG. 9D shows a failure mode of a knife member having a mechanical fuse, in accordance with some embodiments.
• FIGS. 10A-10C show perspective views of knife members having a laminate construction and mechanical fuses, in accordance with some embodiments.
• FIG. 11A shows a side views of a knife member having a mechanical fuse, in accordance with some embodiments.
• FIGS. 11B and 11C show failure modes of the knife member ofFIG. 11A, in accordance with some embodiments.
DETAILED DESCRIPTION OF THE INVENTION
• Cutting implements of surgical stapling and cutting devices can jam while actively cutting tissue. Jamming can occur due to a jamming substance (e.g., bone, tissue, and/or staples) impinging the cutting implement and bringing it to a halt. Often, this situation cannot be easily remedied and requires physical intrusion into the sterile field to physically remove the associated stapling device. Embodiments of a knife member disclosed herein may address these situations by incorporating one or more fused portions configured to control the mechanical failure of the knife member. Such fused portions can fail in a mode to cause the knife blade (also called the cutting blade) to be freed from the jamming substance. A fused portion can be configured to fail by breaking and/or bending one or more portions of the knife member. For example, the fused portion may be configured to fail by material fracture, by plastic deformation, a combination thereof, etc. under particular loading conditions. As another example, the fused portion may be configured to cause the knife member to fail in a particular configuration or in a particular way that reduces jamming, increases retention of the knife member after breakage, improves patient safety, a combination thereof, and the like. The fused portion is termed “fused” because it may be configured to act like a mechanical analog of an electrical fuse, and be designed fail under particular loading conditions.
• FIG. 1 shows a surgical tool70 that includes a proximal chassis72 that can be coupled with an adapter82, an instrument shaft74, and a distal end effector76 having a jaw78 that can be articulated to grip a patient tissue. The proximal chassis includes input couplers that may interface with and be driven by corresponding output couplers of a telesurgical surgery system, such as the system disclosed within Pub. No. US20140183244A1, which is incorporated by reference herein. The input couplers are drivingly coupled with drive shafts that are disposed within the instrument shaft74. The drive shafts are drivingly coupled with the end effector76.
• FIG. 2 shows a demountablyattachable cartridge100 of a linear stapling and cutting surgical instrument, in accordance with many embodiments. Thecartridge100 is configured to removably attach to a jaw of an end effector. The cartridge has aproximal end102 that is attached to the jaw of the end effector and adistal end104 disposed at a corresponding distal end of the jaw of the end effector. Thecartridge100 includes six rows ofstaple openings106, alongitudinal slot108, aproximal knife garage110, adistal knife garage112, and arotational input114. In many embodiments, a staple is disposed in each of the staple openings for deployment there from. Thelongitudinal slot108 accommodates a cutting blade of a knife member (not shown) extending there from as the knife member is moved from theproximal knife garage110 to thedistal knife garage112. In operation, the staples are deployed starting at the cartridgeproximal end102 and proceeding to the cartridgedistal end104. The cutting blade is moved to trail the stapling of the tissue to ensure that only fully stapled tissue is cut.FIG. 3 shows thecartridge100 with an attachedstaple retainer116, which is removed prior to using thecartridge100.
• FIG. 4 is a cross-sectional view showing details of the attachment of thecartridge100 to anend effector118, in accordance with many embodiments. Theend effector118 includes alower jaw120, anupper jaw122, a two degree offreedom wrist124, a rotationally-drivenclamping mechanism126, and a spring loadedcoupling128. Thelower jaw120 is configured to accommodate and support thecartridge100, as well as position thecartridge100 relative to the spring loadedcoupling128. Theupper jaw122 is pivotally coupled with thelower jaw120 to articulate relative to thelower jaw120 to clamp tissue. Theupper jaw122 includes staple forming recesses configured and positioned relative to thestaple openings106 to form the staples into a “B” shape upon deployment of the staples.
• The two degree offreedom wrist124 provides for attachment of theend effector118 to anelongated instrument shaft130 for articulation of theend effector118 about two orthogonal axes relative to theinstrument shaft130. The rotationally-drivenclamping mechanism126 actuates theupper jaw122 relative to thelower jaw120 to securely clamp tissue between the upper and lower jaws. Theclamping mechanism126 is rotationally driven by afirst drive shaft132 disposed internal to theinstrument shaft130.
• The spring-loadedcoupling128 rotationally couples alead screw134 of thecartridge100 with anextension shaft136, which is driven by asecond drive shaft138 disposed internal to theinstrument shaft130. The spring-loadedcoupling128 includes acoil spring140 and acoupling fitting142. In the embodiment shown, the coupling fitting142 employs a three-lobe spline receptacle that interfaces with three-sided external surfaces of therotational input114 and of theextension shaft136. The spring-loadedcoupling142 accommodates angular misalignment of the three-lobe spline that might occur whencartridge100 is installed intoend effector118. The spring-loadedcoupling142 fully engages the three-lobe spline when rotated into angular alignment. Rotation of thelead screw134 is used to translate adrive member144 of thecartridge100. The resulting motion of thedrive member144 is used to deploy the staples and to distally advance aknife member146 of thecartridge100 to cut the clamped tissue down the center of the rows of deployed staples.
• Theend effector118 includes a first universaljoint assembly148 and a second universaljoint assembly150. The first universaljoint assembly148 rotationally couples theclamping mechanism126 to thefirst drive shaft132. The second universaljoint assembly150 rotationally couples theextension shaft136 to thesecond drive shaft138. Each of the first and second universaljoint assemblies148,150 is configured to transmit torque through a range of angles suitable to the range of Pitch and Yaw of theend effector118 relative to theinstrument shaft130. The first andsecond drive shafts132,138 are disposed offset to the centerline of theinstrument shaft130, which may be independently rotated.
• FIG. 5 is an exploded perspective view illustrating components of thecartridge100. The illustrated components include theretainer116, 66staples152, a printed circuit assembly (PCA)spring154, aPCA156, acartridge body158, 22staple pushers160, theknife member146, thelead screw134, thedrive member144, athrust washer162, alead screw nut164, and acover166. Thecartridge body158 has the 66staple openings106 arranged in 6 rows, with 3 rows of thestaple openings106 being disposed on each side of thelongitudinal slot108. Theretainer116 is removably attachable to thecartridge100 and covers thestaple openings106 to retain thestaples152 prior to use of thecartridge100. Thestaple pushers160 interface with thestaples152 and slidingly interface with thecartridge body158. Motion of thedrive member144 along thelead screw134 results in engagement of thestaple pushers160 by distally-facing ramp surfaces176 of thedrive member144 to drive thestaple pushers160 up relative to thecartridge body158 to deploy thestaples152 as thedrive member144 moves towards thedistal end104. Theknife member146 includesproximal protrusions168 anddistal protrusions170. Thecover166 is attached to thecartridge body158.
• FIG. 6 illustrates components of thecartridge100 related to the actuation of theknife member146 from a starting position (illustrated) in which theknife member146 is shielded by theproximal garage110 to an ending position (not illustrated) in which theknife member146 is shielded by thedistal garage112. Thelead screw134 is mounted for rotation relative to thecartridge body158 and extends along the length of thecartridge body158. Thedrive member144 is internally threaded and is coupled with thelead screw134 and slidably mounted in thecartridge body158 for translation along thelead screw134 in response to rotation of thelead screw134. Thedrive member144 includes one or more distally-facingramps176 configured to engage thestaple pushers160 as thedrive member144 is advanced toward thedistal end104 of thecartridge body100. Theknife member146 includes a knife blade178 (also called cutting blade178), thebody portion180, theproximal protrusions168 extending from opposite sides of thebody portion180, and theproximal protrusions170 also extending from opposite sides of thebody portion180. As will be described in more detail below, when thedrive member144 is advanced distally from its illustrated starting position, theknife member146 remains stationary relative to thecartridge body158 until thedrive member144 contacts thedistal protrusions170 by which theknife member146 is then driven distally by thedrive member144. Near the end of the distal travel of thedrive member144, the distal end of theknife member146 is driven along acam surface182 of thecartridge body158, thereby raising the distal end of theknife member146 to lower theknife blade178 below anupper surface184 of thecartridge body158 and into thedistal garage112. The knifemember body portion180 is constrained by opposing surfaces of thecartridge body158 that define thelongitudinal slot108. The knife proximal anddistal protrusions168,170 extend from opposite sides of the knifemember body portion180 beyond the width of thelongitudinal slot108, thereby serving to constrain theknife member146 vertically relative to thecartridge body158 and thedrive member144.
• FIGS. 7A through 7D illustrate the interaction of components of thecartridge100 during the actuation of theknife member146 from its starting position in theproximal garage110 to its final position in thedistal garage112.FIG. 7A shows three different positions of theknife member146 relative to thecartridge body158, specifically a starting proximal-most position, an intermediate position, and a distal position just before the distal end of theknife member146 is driven up the cartridgebody cam surface182.
• As shown inFIGS. 7A and 7B, in the starting proximal-most position, thedrive member144 is positioned at the proximal end of thelead screw134 and the knife memberproximal protrusions168 are disposed withinreceptacles198 in thecartridge body158. The drive member upper surfaces194 interface with the knife memberproximal protrusions168 to retain theproximal protrusions168 in thecartridge body receptacles198, thereby securing engagement between theproximal protrusions168 and thecartridge body receptacles198. The knife memberdistal protrusions170 and the distal end of the knife are trapped between acentral cavity ceiling200 of thecartridge body158 and thelead screw134 and the knifemember body portion180 is disposed within thelongitudinal slot108, thereby restraining theknife member146 in a substantially fixed position and orientation relative to thecartridge body158.
• From the starting proximal-most position, rotation of thelead screw134 drives thedrive member144 distally along thelead screw134. Throughout a starting “lost-motion” portion of the distal motion of thedrive member144 along thelead screw134, theproximal protrusions168 remain trapped in thecartridge body receptacles198 by the drive member upper surfaces194. When thedrive member144 has moved distally to a point where the drive member distal surfaces196 contact the knife memberdistal protrusions170, the drive member proximal receptacles192 are disposed below thecartridge body receptacles198, thereby permitting theknife member146 to rotate to transfer theproximal protrusions168 from thecartridge body receptacles198 to the drive member proximal receptacles192. To facilitate this transfer, adistal surface202 of thecartridge body receptacles198 is sloped as illustrated to enhance the transfer by imparting a downward force component on theproximal protrusions168 as the knife member distal surfaces196 drive theknife member146 distally via contact with the knife memberdistal protrusions170.
• FIG. 7C illustrates interaction between thedrive member144, theknife member146, and thecartridge body158 following the “lost motion” portion of the distal motion of thedrive member144 along thelead screw134. After the drive member distal surfaces196 come into contact with the knife memberdistal protrusions170 causing theknife member146 to rotate to transfer theproximal protrusions168 into the drive member proximal receptacles192, continued rotation of thelead screw134 results in continued distal motion of thedrive member144 and corresponding distal motion of theknife member146. During this continued distal motion, theknife member146 is constrained by both the drive memberdistal protrusions170 interaction with theceiling200 of thecartridge body158 and the knifemember body portion180 interaction within thelongitudinal slot108 of thecartridge body158.
• FIGS. 7A and 7D illustrate interaction between thedrive member144, theknife member146, and the cartridge body158 (particularly thecam surface182 of the cartridge body158) during a terminal portion of the distal motion of thedrive member144 along thelead screw134. As thedrive member144 is advanced distally near the end of its travel along thelead screw134, the distal end of theknife member146 comes into contact with thecam surface182 and is subsequently driven along thecam surface182 until reaching the ending distal-most position illustrated inFIG. 7D in which thedrive member144 has reached the end of its travel along thelead screw134. As a result of the distal end of theknife member146 being driven along the upwardsloping cam surface182, theknife member146 rotates approximately around the knife memberproximal protrusions168, thereby lowering theknife blade178 into thedistal garage112.
• In some cases, theknife member146 can jam in the modes shown atFIGS. 7C-7D, which are modes where theknife member146 can actively cut tissue. Jamming can occur due to a jamming substance (e.g., bone, tissue, and/or staples) impinging theknife member146 and bringing it to a halt. Often, this situation cannot be easily remedied and requires physical intrusion into the sterile field to physically remove the associated stapling device. Embodiments of theknife member146 may address these situations by incorporating a fused portion, which is configured to fail in a mode where theknife blade178 is placed below thelongitudinal slot108 and freed from the jamming substance. The fused portion can be configured to fail by breaking and/or bending one or more portions of theknife member146.
• FIG. 8A shows aknife member200 having afirst frame portion202A spanning approximately betweenknife blade178 andproximal protrusion168. Theknife member200 also includes asecond frame portion204 spanning approximately between thefirst frame portion202 anddistal protrusion170. Here, thefirst frame portion202A includes anopening206 defining a spatial separation between alower strut208A and anupper strut210.Upper strut210 includes a fusedportion212, which can be configured as a notched or thinned portion having a reduced thickness when compared to another part of theupper strut210, such as a portion near or adjacent to the fusedportion212. Thus, thefirst frame portion202A comprises the fusedportion212 and can be termed a fused frame portion. In some embodiments, the fusedportion212 is the thinnest portion of theupper strut210.
• In use, distal movement of theknife blade178 will apply torque to theproximal protrusion168 and thereby place theupper strut210 in tension. Jamming of the device increases this tension greatly as thelead screw134 continuously tries to drive thedrive member144 forward against the jam. Once this tension meets a predetermined amount of force, the fused portion will fracture. After the fracture occurs, theknife blade178 continually applies torque toproximal protrusion168, which then causes the lower strut to bend downward, and thereby place the knife blade underneath thelongitudinal slot108 and alleviating the jam. The thickness of thelower strut208A can be tuned mechanically for failure force by changes in geometry or material. The embodiment of aknife member214 shown atFIG. 8B is an example of a geometric change. Theknife member214 is identical to theknife member200 except that theknife member214 comprises afirst frame portion202B with alower strut208B that is thinner than thelower strut208A shown atFIG. 8A. Thus, the knife member2014 will bend at a lower threshold of force in comparison to theknife member200. Other embodiments may tune mechanically for failure force by adjusting the geometry or material of one or more parts of the knife member.
• FIG. 8C shows aknife member216 similar to theknife member200 depicted atFIG. 8A. However, thefirst frame member202C comprises a fused portion212C that does not include a notched portion. Instead, the fused portion212C comprises a thinner section of material along theupper strut210 that is thinner relative to another part of theupper strut210. In some embodiments, the fusedportion212 comprises the thinnest section of material of theupper strut210. Hence, failure will generally occur at the fusedportion212 due to it being the weakest portion of thefirst frame portion202C.
• FIG. 8D shows a typical failure mode of the embodiments shown atFIGS. 8A-8C. Here, the fusedportion212 has fractured within the first frame portion (e.g.first frame portions202A,202B,202C). However, thefirst frame portion202A,202B, or202C and thesecond frame portion204 remain linked by thelower strut208A,208B, or208C, respectively. In the failure shown inFIG. 8D, thelower strut208D is now significantly bent.
• FIG. 9A shows aknife member218 having the fusedportion212 located at thesecond frame portion204. The fusedportion212 is configured as a thinned portion of material of thesecond frame portion204, and the fused portion is thinner relative to another part of thesecond frame portion204, such as a portion near or adjacent to the fusedportion212. Hence, failure will occur at the fusedportion212 due to it being the weakest portion of thesecond frame portion204. In use, distal movement of theknife blade178 will apply torque to theproximal protrusion168 and thereby place thesecond frame portion204 in tension. Jamming increases this tension greatly as thelead screw134 continuously tries to drive thedrive member144 forward against the jam. Once this tension meets a predetermined amount of force, the fusedportion212 will fracture or elastically deform to a great degree, essentially breaking theknife member218 into two parts. After the failure occurs theknife blade178 continually applies torque toproximal protrusion168, which then causes theknife blade178 andfirst frame portion202 to rotate clockwise, and thereby place theknife blade178 underneath thelongitudinal slot108 and alleviate the jam.
• FIG. 9B also shows aknife member220 having the fusedportion212 located at thesecond frame portion204, and such asecond frame portion204 can be termed a fused frame portion. Here, the fusedportion212 is defined by a notched portion, which will fracture in response to sufficient force because it has the smallest cross-sectional area of thesecond frame portion204 and is a location of high stress concentration whenknife member220 is jammed. In use, the failure mode will be similar to that ofknife member218, with theknife member220 breaking into two separate parts.
• FIG. 9C shows aknife member222 having the fusedportion212 located at thesecond frame portion204. Here, thesecond frame portion204 includes anopening224 defining a spatial separation between alower strut226 and an upper strut228. Upper strut228 includes the fusedportion212, which here is configured as a notched or thinned portion having a reduced thickness relative to another portion of the upper strut228, such as a portion near or adjacent to the fusedportion212. In use, the fusedportion204 will fracture or elastically deform to a great degree. However, unlike theknife member218 shown atFIG. 9A, theknife member222 will not break into two parts because thelower strut226 bends, but remains connected between thefirst frame portion202 and thesecond frame portion204.
• FIG. 9D shows a typical failure mode of the embodiments shown atFIGS. 9A and 9B. Here, the fused portion has fractured within thesecond frame portion204, separating thefirst frame portion202 from thesecond frame portion204.
• FIGS. 10A and 10B show aknife member230 having a laminate construction in which portions of thefirst frame portion202 and thesecond frame portion204 are formed from first andsecond sheets232,234 of metal. Theknife member230 can be formed from a metal stamping that is folded atupper bend portion236. This can provide enhanced rigidity for coupling of theknife member230 to thedrive member144. Theknife blade178 is formed from only thesecond sheet234, as is the fusedportion212 located within thefirst frame portion202. Hence, the failure mode of the fusedportion212 will bending at that location, as opposed to a fracture, to place theknife blade178 underneath thelongitudinal slot108 and alleviate a jam.
• FIG. 10C shows aknife member238 having a similar laminate construction as shown atFIGS. 10A and 10B. However, here the fusedportion212 comprises a thin portion of material between anupper notch240 and anopening242 of thesecond sheet234. This thin portion is thinner than portions ofknife member238 on the sides ofnotch240 The fusedportion212 will fracture because it has the smallest cross-sectional area of thefirst frame portion202. In turn, alower portion244 of the first frame portion will bend and prevent thefirst frame portion202 andsecond frame portion204 from separating.
• FIG. 11A shows aknife member246 in which the fusedportion212 is an elongate portion of thesecond frame portion204. The fusedportion212 has a relatively large length to width ratio and will be placed into tension when theknife blade178 jams. Hence the fused portion is a section configured for elastic deformation such that a necking portion is formed. The necking portion can bend as it forms the smallest cross-sectional area of thesecond frame portion204 to place theknife blade178 underneath thelongitudinal slot108. This failure mode is depicted atFIG. 11B. However, in some embodiments, the fusedportion212 will eventually fracture, thereby separating thefirst frame portion202 from thesecond frame portion204. This failure mode is depicted atFIG. 11C.
• The methods disclosed herein can be employed in any suitable application. For example, the methods disclosed herein can be employed in surgical instruments, manual or powered, hand-held or telesurgical, directly controlled or teleoperated, for open or minimally invasive (single or multi-port) procedures.
• Other variations are within the spirit of the present invention. For example, while fused portions are depicted at one of the first and second frame portions, in some embodiments, both frame portions can includes fused portions. Also, although the failures of the fused portions are generally described in terms of material fracture, the fused portions of some embodiments may fail by plastic deformation or some other type of hardware failure. Thus, while the invention is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims.
• The term “force” is to be construed as encompassing both force and torque (especially in the context of the following claims), unless otherwise indicated herein or clearly contradicted by context. The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
• Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
• All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

Claims (29)

1. A surgical knife member comprising:

a blade portion for operation within a surgical stapling device;

a first frame portion extending from the blade portion to a first connection portion that is movably connectable to the surgical stapling device; and

a second frame portion extending from the first frame portion to a second connection portion that is movably connectable to the surgical stapling device,

wherein a fused frame portion selected from the group consisting of the first frame portion and second frame portion comprises a fused portion that fails when a predetermined amount of force is applied to the fused portion.

2. The surgical knife member ofclaim 1, wherein the fused portion comprises a notched portion.

3. The surgical knife member ofclaim 1, wherein the fused portion comprises a thinner section that is thinner relative to the remainder of the fused frame portion.

4. The surgical knife member ofclaim 1, wherein the fused portion fails by fracturing when the predetermined amount of force is applied to the fused portion.

5. The surgical knife member ofclaim 1, wherein the fused portion fails by bending when the predetermined amount of force is applied to the fused portion.

6. The surgical knife member ofclaim 1, wherein the fused frame portion comprises an opening proximate to the fused portion.

7. (canceled)

8. The surgical knife member ofclaim 1, wherein:

the fused frame portion comprises a first strut and a second strut;

the first strut is separated from the second strut by an opening; and

the fused portion comprises a notched portion in the first strut.

9. (canceled)

10. The surgical knife member ofclaim 1, wherein:

the fused frame portion comprises the first frame portion; and

the second frame portion comprises an elongated strut that elastically deforms toward the fused portion in response to the predetermined amount of force being applied to the fused portion.

11. (canceled)

12. The surgical knife member ofclaim 1, wherein:

the first frame portion comprises a laminated construction comprising a first sheet of material and a second sheet of material; and

the blade portion and the fused portion are portions of the second sheet of material.

13. (canceled)

14. A surgical stapling cartridge assembly comprising:

a cartridge that is removably attachable to a jaw of an end effector of a surgery tool, the cartridge comprising plurality of staples arranged along a slot;

a drive member that is drivable along the slot; and

a knife member that is carried by the drive member, the knife member having a blade portion that extends above the slot, wherein the knife member comprises a fused portion that fails and recedes the blade portion beneath the slot when a predetermined amount of force is applied to the fused portion.

15. The surgical stapling cartridge assembly ofclaim 14, wherein the knife member comprises:

a first frame portion extending from the blade portion to a first connection portion that is moveably connectable to the drive member;

a second frame portion extending from the first frame portion to a second connection portion, the second connection portion for moveable connection that is moveably connectable to the drive member,

wherein at least one frame portion selected from the group consisting of the first frame portion and the second frame portion comprises the fused portion.

16. The surgical stapling cartridge assembly ofclaim 15, wherein the fused portion comprises a notched portion.

17. The surgical stapling cartridge assembly ofclaim 15, wherein the fused portion comprises a relatively thin section relative to the remainder of the at least one frame portion.

18. The surgical stapling cartridge assembly ofclaim 15, wherein the fused portion fails by fracturing when the predetermined amount of force is applied to the fused portion.

19. The surgical stapling cartridge ofclaim 15, wherein the fused portion fails by bending when the predetermined amount of force is applied to the fused portion.

20. The surgical stapling cartridge assembly ofclaim 15, wherein the at least one first frame portion comprises an opening proximate to the fused portion.

21. (canceled)

22. The surgical stapling cartridge ofclaim 15, wherein:

the at least one frame portion comprises a first strut and a second strut that is separated from the first strut by an opening; and

the fused portion comprises a notched portion of the first strut.

23. (canceled)

24. The surgical stapling cartridge ofclaim 15, wherein:

the at least one frame portion comprises the first frame portion; and

the second frame portion comprises an elongated strut that elastically deforms into the fused portion when the predetermined amount of force is applied to the fused portion.

25. (canceled)

26. The surgical stapling cartridge assembly ofclaim 15, wherein;

the first frame portion and the second frame portion comprise a laminated construction comprising a first sheet and a second sheet; and

the blade portion and the fused portion are located on the second sheet.

27. (canceled)

28. A surgical knife member comprising:

a blade portion for operation within a surgical stapling device;

a first frame portion extending from the blade portion to a first connection portion that is movably connectable to the surgical stapling device; and

a second frame portion extending from the first frame portion to a second connection portion that is movably connectable to the surgical stapling device,

wherein a fused frame portion selected from the group consisting of the first frame portion and second frame portion comprises a fused portion, the fused portion comprising a notched portion and fails by fracturing in response to a predetermined amount of force is applied to the surgical knife member.

29. The surgical knife member ofclaim 28, wherein the fused frame portion is the first frame portion, the first frame portion comprises a first strut and a second strut separated from the first strut by an opening, the first strut comprises the notched portion, and the second frame portion comprises an elongated strut configured to elastically deform toward the fused portion in response to the predetermined amount of force.

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